Radioreceiver



July 1, 1930. A. sfcLARKr-z 1,769,256

RADIORECEIVER Filed March 24, 1927 2 Sheets-Sheet 1 E INVENTOR wlms Y A.5 CZar/(e.

BY M WITNESS I Ads-Cl rk y 1930. A. s. CLARKE 1,769,256

RADIORECEIVER Fi led March '24, 1927 2 Sheets-Sheet 2 -Erma:

OUTPUT TERMINAES q 41 LQUD $PI:}:;R INVENTOR ATTORNEY}.

Patented July 1, 1930 n'LLENs. CLARKE, on DANVILLE, VIRGINIA ana Inn'monnonrvnn Application filed March' 24, 1927., Serial IiTo. 178,049.

This invention relates to a remote control for radio receivers.

The prime object of the invention is to provide means whereby the volumeof the output of a radio receiver may be easily and accuratelycontrolled from a point remote from the radio receiving set.

It is also an object of the invention that the volume control means beadapted to be employed in connection with any type of receivingapparatus without interfering with the operation thereofin reception ofsignals.

It is also within the scope of the invention that the volume controlmeans be easy in operation and permit the user to utilize the same ingiving vocal or instrumental music received the desired softnessorloudness at any time.

In carrying out my invention I employ a suitable resistance which may beat a remote point to a radio set, suitable wires are extended from theresistance to the radio set so that the resistance may be connected in acircuit of the radio s-etwhereby the volume of the set may be controlledby the resistance.-

Thelinventlonvis illustratedby way of example in the accompanyingdrawings, in v I t 'which:

Figure 1 is a perspectiveview showing a radio receiving set with myinvention applied, and

Figures 2 to 6 are diagrammatic views illustrating different Ways ofapplying my invention to a radio receiving system;

Referring to the drawings more particularly, and particularly to Figures2and 4:, 10

indicates an antenna circuit which may be a coupled to the grid-filamentcircuit of a tube 11. At 12'is shown the primary winding of a radiofrequency current coupling or transformer and at 18 the secondary ofsaid coupling 12 is connectedin the plate circuit of the tube 11 in theusual manner, and the remainder of the, system for detecting the radiofrequency currents and amplifying the same may be made in the usualmanner. Inorder to control the volume of the receiving apparatus shownin Figure 2,

interpose in theplate circuit of the tube 11 a condenser. llandaboutthecondenser I connect the wires 15 which are extended to a remotepoint, such as thechair of the operator ofthe radio receiving set, andthe remote ends of ,wires15 connected to an" adjustable resistance 16.]The condenser 14 permits ,a by-pass for radio frequency curs rents, Theres1stan'ce16 1s in series with the plate circuit of tube 11 and llh6directh current of said circuit; must flow, through; 3

said resistance whereby the outputvolumee ofthe receiving set may. becontrolled. In Figure 4, I- have illustratedan" adjust able resistance17 locatedat a remote point,

wires- 18 which may constitute a Cable, lead; to a plug 19. Wires20and121.arebXtendedg from the opposite ends oftransformer 13;,and'connected to a suitable jack'indicatedi at '22.The'transformervlififmay be eithertheaudio or radio frequency type-rAs-is 1 apparent from the diagram the, resistance 17 can be connectedaboutthe secondary of. the transformerfwin ding 113 and serveto" controlthe output volume of the systems:

Referringto Figure 1, 23 indicates a radio receiving ca'binet24, a loud,speaker,

and, 25a table; Assuming the system housed within {the cabinet 23 :issimilarftothat-shown infFigure' 2 on-thab shown inp Figure 4, thenthecable 26 would indicate: the cable for the wires leading to asuitably mounted resistance as indicated at 27;v As a is apparent, theresistance box or,circuit-,27,,

could be placed at .a dist'anceflvof the cabineti 28 is a part, and saidresistancev 29 utilized for controlling the output of thereceiving 9apparatus. Referring I an electron tube-which has connected in its;platecircuit the primary winding 81 of an 3 audio transformer, thesecondary of said to Figures 6, indicates V a cable extending therefromcomprising the two wires 35 and said wires connected at their endsremote from the plug 34 to a suit-- nected to the output terminals ofthereceiving apparatus and the terminals of a high resistance potentiometershown at 4:0. The wire 29 preferably has inserted therein a condenserll. The one end of wire 39 may be connected to a terminal of a loudspeaker and an output terminal of the receiving apparatus connected tothe remaining terminal of the loud speaker. 7 serves to'stop flow ofdirect current through the loud speaker if such is inserted in circuitof secondary 32 and the potentiometer 40 serves to control volume ofloud speaker connected as previously pointed out.

While I have shown various ways by which my invention may be practicedit is to be understood that I am aware of the fact that a suitableresistance might be utilized in other circuits of a radio receivingapparatus with equal results, as for example, a resistance might beinserted in the filament circuit of one or more tubes of a set and thevolume of the set controlled by regulating the brilliancy at which-thefilaments are burned.

I claim a 1. The combination with a radio receiving apparatus, of anaddedswitchjack arranged in the out-put circuit ofthe apparatus, alength ofconductor cable, a'rheostat connected in circuit with certainof the conductors of said cable toward the outer end thereof, acondenser connected in circuit with one of the conductors of said cableand said rheostat,"and a plug connected to the conductors of the cableat the opposite end thereof and adapted to be engaged with said switchjack whereby the volume of tone reproduction at a loud speaker in thesaid out-put circuit may be varied at will by manipulation'o'f saidrheostat from a point remote from the said apparatus. 7

2. The combination wtih a radio receiving apparatus, of an added switchjack arranged in the output circuit of the apparatus, a casing separatefromsaid apparatus, a length of three wire conductor cable leading fromsaid apparatus to said casing, a

variable resistance mounted in said casing The condenser 4:1

and having the resistor element thereof connected across the free endsof two of the conductors of said cable, a condenser also mounted withinsaid casing and connected in circuit with the other of said conductorsof said cable andto the movable element of lation of the movable elementof said rheostat.

ALLEN CLARKE.

